| Step | Hyp | Ref
 | Expression | 
| 1 |   | simpr 110 | 
. . . 4
⊢ ((𝜑 ∧ 𝑦<P 𝐵) → 𝑦<P 𝐵) | 
| 2 |   | ltrelpr 7572 | 
. . . . . . . 8
⊢
<P ⊆ (P ×
P) | 
| 3 | 2 | brel 4715 | 
. . . . . . 7
⊢ (𝑦<P
𝐵 → (𝑦 ∈ P ∧
𝐵 ∈
P)) | 
| 4 | 3 | simpld 112 | 
. . . . . 6
⊢ (𝑦<P
𝐵 → 𝑦 ∈ P) | 
| 5 | 4 | adantl 277 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑦<P 𝐵) → 𝑦 ∈ P) | 
| 6 | 3 | simprd 114 | 
. . . . . 6
⊢ (𝑦<P
𝐵 → 𝐵 ∈ P) | 
| 7 | 6 | adantl 277 | 
. . . . 5
⊢ ((𝜑 ∧ 𝑦<P 𝐵) → 𝐵 ∈ P) | 
| 8 |   | ltdfpr 7573 | 
. . . . 5
⊢ ((𝑦 ∈ P ∧
𝐵 ∈ P)
→ (𝑦<P 𝐵 ↔ ∃𝑠 ∈ Q (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) | 
| 9 | 5, 7, 8 | syl2anc 411 | 
. . . 4
⊢ ((𝜑 ∧ 𝑦<P 𝐵) → (𝑦<P 𝐵 ↔ ∃𝑠 ∈ Q (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) | 
| 10 | 1, 9 | mpbid 147 | 
. . 3
⊢ ((𝜑 ∧ 𝑦<P 𝐵) → ∃𝑠 ∈ Q (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵))) | 
| 11 |   | simprrr 540 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑦<P 𝐵) ∧ (𝑠 ∈ Q ∧ (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) → 𝑠 ∈ (1st
‘𝐵)) | 
| 12 |   | suplocexpr.b | 
. . . . . . . . . 10
⊢ 𝐵 = 〈∪ (1st “ 𝐴), {𝑢 ∈ Q ∣ ∃𝑤 ∈ ∩ (2nd “ 𝐴)𝑤 <Q 𝑢}〉 | 
| 13 | 12 | fveq2i 5561 | 
. . . . . . . . 9
⊢
(1st ‘𝐵) = (1st ‘〈∪ (1st “ 𝐴), {𝑢 ∈ Q ∣ ∃𝑤 ∈ ∩ (2nd “ 𝐴)𝑤 <Q 𝑢}〉) | 
| 14 |   | npex 7540 | 
. . . . . . . . . . . . 13
⊢
P ∈ V | 
| 15 | 14 | a1i 9 | 
. . . . . . . . . . . 12
⊢ (𝜑 → P ∈
V) | 
| 16 |   | suplocexpr.m | 
. . . . . . . . . . . . 13
⊢ (𝜑 → ∃𝑥 𝑥 ∈ 𝐴) | 
| 17 |   | suplocexpr.ub | 
. . . . . . . . . . . . 13
⊢ (𝜑 → ∃𝑥 ∈ P ∀𝑦 ∈ 𝐴 𝑦<P 𝑥) | 
| 18 |   | suplocexpr.loc | 
. . . . . . . . . . . . 13
⊢ (𝜑 → ∀𝑥 ∈ P ∀𝑦 ∈ P (𝑥<P
𝑦 → (∃𝑧 ∈ 𝐴 𝑥<P 𝑧 ∨ ∀𝑧 ∈ 𝐴 𝑧<P 𝑦))) | 
| 19 | 16, 17, 18 | suplocexprlemss 7782 | 
. . . . . . . . . . . 12
⊢ (𝜑 → 𝐴 ⊆ P) | 
| 20 | 15, 19 | ssexd 4173 | 
. . . . . . . . . . 11
⊢ (𝜑 → 𝐴 ∈ V) | 
| 21 |   | fo1st 6215 | 
. . . . . . . . . . . . 13
⊢
1st :V–onto→V | 
| 22 |   | fofun 5481 | 
. . . . . . . . . . . . 13
⊢
(1st :V–onto→V → Fun 1st ) | 
| 23 | 21, 22 | ax-mp 5 | 
. . . . . . . . . . . 12
⊢ Fun
1st | 
| 24 |   | funimaexg 5342 | 
. . . . . . . . . . . 12
⊢ ((Fun
1st ∧ 𝐴
∈ V) → (1st “ 𝐴) ∈ V) | 
| 25 | 23, 24 | mpan 424 | 
. . . . . . . . . . 11
⊢ (𝐴 ∈ V → (1st
“ 𝐴) ∈
V) | 
| 26 |   | uniexg 4474 | 
. . . . . . . . . . 11
⊢
((1st “ 𝐴) ∈ V → ∪ (1st “ 𝐴) ∈ V) | 
| 27 | 20, 25, 26 | 3syl 17 | 
. . . . . . . . . 10
⊢ (𝜑 → ∪ (1st “ 𝐴) ∈ V) | 
| 28 |   | nqex 7430 | 
. . . . . . . . . . 11
⊢
Q ∈ V | 
| 29 | 28 | rabex 4177 | 
. . . . . . . . . 10
⊢ {𝑢 ∈ Q ∣
∃𝑤 ∈ ∩ (2nd “ 𝐴)𝑤 <Q 𝑢} ∈ V | 
| 30 |   | op1stg 6208 | 
. . . . . . . . . 10
⊢ ((∪ (1st “ 𝐴) ∈ V ∧ {𝑢 ∈ Q ∣ ∃𝑤 ∈ ∩ (2nd “ 𝐴)𝑤 <Q 𝑢} ∈ V) →
(1st ‘〈∪ (1st
“ 𝐴), {𝑢 ∈ Q ∣
∃𝑤 ∈ ∩ (2nd “ 𝐴)𝑤 <Q 𝑢}〉) = ∪ (1st “ 𝐴)) | 
| 31 | 27, 29, 30 | sylancl 413 | 
. . . . . . . . 9
⊢ (𝜑 → (1st
‘〈∪ (1st “ 𝐴), {𝑢 ∈ Q ∣ ∃𝑤 ∈ ∩ (2nd “ 𝐴)𝑤 <Q 𝑢}〉) = ∪ (1st “ 𝐴)) | 
| 32 | 13, 31 | eqtrid 2241 | 
. . . . . . . 8
⊢ (𝜑 → (1st
‘𝐵) = ∪ (1st “ 𝐴)) | 
| 33 | 32 | eleq2d 2266 | 
. . . . . . 7
⊢ (𝜑 → (𝑠 ∈ (1st ‘𝐵) ↔ 𝑠 ∈ ∪
(1st “ 𝐴))) | 
| 34 | 33 | ad2antrr 488 | 
. . . . . 6
⊢ (((𝜑 ∧ 𝑦<P 𝐵) ∧ (𝑠 ∈ Q ∧ (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) → (𝑠 ∈ (1st
‘𝐵) ↔ 𝑠 ∈ ∪ (1st “ 𝐴))) | 
| 35 | 11, 34 | mpbid 147 | 
. . . . 5
⊢ (((𝜑 ∧ 𝑦<P 𝐵) ∧ (𝑠 ∈ Q ∧ (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) → 𝑠 ∈ ∪ (1st “ 𝐴)) | 
| 36 |   | suplocexprlemell 7780 | 
. . . . 5
⊢ (𝑠 ∈ ∪ (1st “ 𝐴) ↔ ∃𝑧 ∈ 𝐴 𝑠 ∈ (1st ‘𝑧)) | 
| 37 | 35, 36 | sylib 122 | 
. . . 4
⊢ (((𝜑 ∧ 𝑦<P 𝐵) ∧ (𝑠 ∈ Q ∧ (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) →
∃𝑧 ∈ 𝐴 𝑠 ∈ (1st ‘𝑧)) | 
| 38 |   | simprl 529 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑦<P 𝐵) ∧ (𝑠 ∈ Q ∧ (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) → 𝑠 ∈
Q) | 
| 39 | 38 | ad2antrr 488 | 
. . . . . . . 8
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → 𝑠 ∈ Q) | 
| 40 |   | simprrl 539 | 
. . . . . . . . 9
⊢ (((𝜑 ∧ 𝑦<P 𝐵) ∧ (𝑠 ∈ Q ∧ (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) → 𝑠 ∈ (2nd
‘𝑦)) | 
| 41 | 40 | ad2antrr 488 | 
. . . . . . . 8
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → 𝑠 ∈ (2nd ‘𝑦)) | 
| 42 |   | simpr 110 | 
. . . . . . . 8
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → 𝑠 ∈ (1st ‘𝑧)) | 
| 43 |   | rspe 2546 | 
. . . . . . . 8
⊢ ((𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝑧))) →
∃𝑠 ∈
Q (𝑠 ∈
(2nd ‘𝑦)
∧ 𝑠 ∈
(1st ‘𝑧))) | 
| 44 | 39, 41, 42, 43 | syl12anc 1247 | 
. . . . . . 7
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → ∃𝑠 ∈ Q (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝑧))) | 
| 45 | 4 | ad4antlr 495 | 
. . . . . . . 8
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → 𝑦 ∈ P) | 
| 46 | 19 | ad4antr 494 | 
. . . . . . . . 9
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → 𝐴 ⊆ P) | 
| 47 |   | simplr 528 | 
. . . . . . . . 9
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → 𝑧 ∈ 𝐴) | 
| 48 | 46, 47 | sseldd 3184 | 
. . . . . . . 8
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → 𝑧 ∈ P) | 
| 49 |   | ltdfpr 7573 | 
. . . . . . . 8
⊢ ((𝑦 ∈ P ∧
𝑧 ∈ P)
→ (𝑦<P 𝑧 ↔ ∃𝑠 ∈ Q (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝑧)))) | 
| 50 | 45, 48, 49 | syl2anc 411 | 
. . . . . . 7
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → (𝑦<P 𝑧 ↔ ∃𝑠 ∈ Q (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝑧)))) | 
| 51 | 44, 50 | mpbird 167 | 
. . . . . 6
⊢
(((((𝜑 ∧ 𝑦<P
𝐵) ∧ (𝑠 ∈ Q ∧
(𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) ∧ 𝑠 ∈ (1st ‘𝑧)) → 𝑦<P 𝑧) | 
| 52 | 51 | ex 115 | 
. . . . 5
⊢ ((((𝜑 ∧ 𝑦<P 𝐵) ∧ (𝑠 ∈ Q ∧ (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) ∧ 𝑧 ∈ 𝐴) → (𝑠 ∈ (1st ‘𝑧) → 𝑦<P 𝑧)) | 
| 53 | 52 | reximdva 2599 | 
. . . 4
⊢ (((𝜑 ∧ 𝑦<P 𝐵) ∧ (𝑠 ∈ Q ∧ (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) →
(∃𝑧 ∈ 𝐴 𝑠 ∈ (1st ‘𝑧) → ∃𝑧 ∈ 𝐴 𝑦<P 𝑧)) | 
| 54 | 37, 53 | mpd 13 | 
. . 3
⊢ (((𝜑 ∧ 𝑦<P 𝐵) ∧ (𝑠 ∈ Q ∧ (𝑠 ∈ (2nd
‘𝑦) ∧ 𝑠 ∈ (1st
‘𝐵)))) →
∃𝑧 ∈ 𝐴 𝑦<P 𝑧) | 
| 55 | 10, 54 | rexlimddv 2619 | 
. 2
⊢ ((𝜑 ∧ 𝑦<P 𝐵) → ∃𝑧 ∈ 𝐴 𝑦<P 𝑧) | 
| 56 | 55 | ex 115 | 
1
⊢ (𝜑 → (𝑦<P 𝐵 → ∃𝑧 ∈ 𝐴 𝑦<P 𝑧)) |